U4 



ELEVENTH LECTURE. 



which surrounds the follicle with a reticular passage, and com 

 mences in a caecal manner just beneath the epithelium. 



Let us also discuss the Peyerian glandular plates. They 

 belong to the lower portions of the human small intestine, 

 and consist, according to their extent, of a very unequal 

 number of aggregated lymphoid follicles. In mammals, where 

 however great mutability prevails, they may also be met 

 with in the large intestine. The human processus vermi- 

 formis, and in still higher development that of the rabbit, 

 forms an enormously developed continuous Peyer's plate. 



The shape of our follicle changes according to the species 

 of animal. They are rounded in man (Fig. 109) and in the 

 Guinea-pig, and strawberry-shaped in the small intestine of 

 the rabbit, while in the vermiform process of the latter animal 



Fig. 109. — Vertical section through a human Peyer's patch : a, intestinal villi; h, Lieberlciihn- 

 ian glands ; c, muscular layer of the mucous membrane ; d, apex of the follicle ; f, basis portion ; 

 g; lymph-passages around the follicle ; i, at the base of the same ; k, lymphatics of the sub-mucous 

 tissue ; /, lymphoid tissue of the latter. 



an elongated thing, reminding one of the sole of a shoe, is 

 met with. A similar appearance is presented by the Peyerian 

 follicles in the ileum of the ox. 



Let us now pass to a closer analysis of our structure. 



